Expert systems offer many advantages to a variety of problem- solving endeavors. These advantages may, in particular, increase the ability of health care professionals to deliver services by assisting in the prescription of appropriate devices or treatments. Specifically, this project addresses the feasibility of developing an expert system to assist in prescribing electronic augmentative communication devices. The typical device prescription may be less than adequate due to three factors: (1) the rather large population of nonspeaking individuals in the United States (approximately one million), (2) the relatively small number of centers providing comprehensive augmentative communication services, and (3) the rapidly expanding commercial market (approximately $10 million annually). The proposed system will model a team approach to augmentative communication device prescription and include all areas of device characteristics (selection technique, language requirements, output modes, and portability) and of client capabilities and needs (communication, cognitive, motor, sensory, and social). The system will demonstrate the specific advantages of the expert systems approach, including storage and dissemination of expertise, use of heuristic knowledge, modifiability, and query capabilities for explanation and justification of recommendation. The system will be evaluated using case information from published and unpublished sources (some in-house). A small-sector prototype of this expert system demonstrated that the project could be completed but a system which utilizes all information about devices and about nonspeaking persons has not been built. Development of the proposed system will require all aspects of knowledge engineering (expert systems programming), including knowledge representation form, knowledge acquisition, and user interface issues, through all stages of expert system building. This will permit an evaluation of the feasibility of the application of this technology to the field of augmentative communication.